A mobile communication system has been developed to provide a voice service, while guaranteeing activity of users. However, coverage of a mobile communication system has extended up to a data service, as well as the voice service, and currently, an explosive increase in traffic has caused shortage of resources, and since users expect relatively high speed services, an advanced mobile communication system is required.
Requirements of a next-generation mobile communication system include accommodation of explosive data traffic, a remarkable increase in a transfer rate per user, accommodation of considerably increased number of connection devices, very low end-to-end latency, and high energy efficiency. To this end, various technologies such as dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband, device networking, and the like, have been researched.
A related art LTE/LTE-A system is designed to have a frame structure with a 1-ms transmission time interval (TTI), in which a data request delay time for a video application is 10 ms.
However, a future 5G technology requires data transmission of lower latency due to the advent of new applications such as a real-time control and tactile Internet, and 5G data request latency is anticipated to be lowered to 1 ms.
However, the related art frame structure having the 1-ms TTI is not able to satisfy 1-ms data request latency.
5G aims at providing data latency reduced to about 10 times that of the related art. As a solution, a communication system having a novel frame structure having a shorter TTI is expected for 5G.
Also, in a 5G system, applications with various requirements such as high capacity, low energy consumption, low cost, a high user data rate, and the like, as well as low latency, are expected to coexist.
5G is required to evolve to a system having a structure different from that of the related art to support various types of applications including both an application requesting ultra-low latency and an application requesting a high data rate. In order to minimize data reception latency of a user equipment (UE), a new frame structure different from that of the related art is required and an influence of a legacy UE due to the new frame structure is required to be minimized.
Also, as a new frame structure for low-latency communication is introduced, 5G may employ a method for aggregating carriers having different frame structures.
Here, a cross-carrier scheduling method regarding frames having different structures is required to be newly defined.